The Charlie Hebdo question doesn't affect my life quality
I would disagree with that. If you meet someone and they tell you about a bunch of conspiracy theories they believe, your estimate of their relative sanity will be dependant on how plausible you think those theories are, and that may impact your life. So, if the vast majority of conspiracy theories are false, but you believe that many have a chance and it's impossible to know, you will accept people as normal who are deluded. (I'm not saying that they deserve anything in particular because they're wrong, but it seems better for you to know rather than not.)
This also allows you to dismiss certain opinions that do matter to you (USE WITH CAUTION!) when the holders also hold many other theries that don't matter. Disclaimer: this refers to theories that you only hear from conspiracy theorists, and can't find "normal" people who believe them. Just because a conspiracy theorist believes something does not make it false. But there are some things that I hear and say "well, all the major advocates also think 9/11 was an inside job/insert conspiracy theory here, so I can safely ignore that", even though the conspiracy theories in question may not be relevant to me. I try to find at least one "clean" advocate for something before taking it seriously as an idea.
tl;dr "The Charlie Hebdo question" and the class of similar ones are relevant to assessing others' rationality.
After the terrorist attacks at Charlie Hebdo, conspiracy theories quickly arose about who was behind the attacks.
People who are critical to the west easily swallow such theories while pro-vest people just as easily find them ridiculous.
I guess we can agree that the most rational response would be to enter a state of aporia until sufficient evidence is at hand.
Yet very few people do so. People are guided by their previous understanding of the world, when judging new information. It sounds like a fine Bayesian approach for getting through life, but for real scientific knowledge, we can't rely on *prior* reasonings (even though these might involve Bayesian reasoning). Real science works by investigating evidence.
So, how do we characterise the human tendency to jump to conclusions that have simply been supplied by their sense of normativity. Is their a previously described bias that covers this case?